1. Field of the Invention:
This invention relates to a coil structure for a transformer and, more particularly, it pertains to a cellulose-free transformer coil construction.
2. Description of the Prior Art:
Conventionally wound transformer coils using round or rectangular enameled wire are designed with uniform layers of wire and paper spaced alternately. The winding sequence is that of applying turns of wire side-by-side helically around the central axis of the coil until a layer is completed. A layer of paper having the full width of the coil is then wrapped over the wire turns to provide insulation. With this insulation in place, the winding is continued with another layer of wire traversing in the opposite direction across the coil width. The dielectric stress from layer to layer is thus very low at one end of the coil and relatively high at the other end. Consequently, the coil size is influenced by the thickness of paper that must be applied to withstand the highest dielectric stress.